#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
class Solution {
public:
    int numOfPairs(vector<string>& nums, string target) {
        int ans=0;
        for(int i=0;i<nums.size();i++){
            for(int j=i+1;j<nums.size();j++){
                string tmp=nums[i]+nums[j];
                if(tmp==target) ans++;
            }
        }
        return ans*2;
    }
};
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);

   	return 0;
}
